Single layer lc oscillator

ABSTRACT

A temperature sensor is provided. The temperature sensor comprises: an inductor-capacitor (LC) oscillator configured; and a look-up table stored in a memory, wherein the look-up table contains a set of frequencies as a function of ambient temperature values, wherein when the LC oscillator is calibrated to a frequency from amongst the set of frequencies, the respective ambient temperature as stored in the look-up table is retrieved.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims benefit of U.S. patent application Ser. No.16/708,831, filed Dec. 10, 2019, which is herein incorporated byreference.

TECHNICAL FIELD

The present disclosure generally relates to oscillators utilized inlow-power transmitters, and more specifically to an inductor-capacitor(LC) oscillator with an inductor implemented within an inlay substrateand employing such an LC oscillator as a temperature sensor.

BACKGROUND

The Internet of things (IoT) is the inter-networking of physicaldevices, vehicles, buildings, and other items embedded with electronics,software, sensors, actuators, and network connectivity that enable theseobjects to collect and exchange data. IoT is expected to offer advancedconnectivity to devices, systems, and services that goes beyondmachine-to-machine (M2M) communications and covers a variety ofprotocols, domains, and applications.

Most IoT devices are wireless devices that collect and transmit data toa central controller. There are a few requirements to be met to allowfor widespread deployment of IoT devices. Such requirements includereliable communication links, low energy consumption, and lowmaintenance costs.

To this end, an IoT device and connected wireless sensors are designedto support low power communication protocols, such as Bluetooth lowenergy (BLE), LoRa, and the like. However, IoT devices utilizing suchprotocols require a power source, such as a coin battery. The relianceon a battery is a limiting factor for electronic devices due to cost,size, lack of durability from environmental effects, requirement forfrequent replacement, and so on. As an alternative to using batteries,power may be harvested and provided from ambient sources, such as light,movement, and electromagnetic power including existing radio frequencywaves. In order to minimize power consumption, IoT devices are designedwith the minimum required components and may implement low-powerconsumption oscillators.

FIG. 1 schematically illustrates a standard BLE transmitter 100, whichincludes a BLE packetizer 110, an oscillator 120, a power source 130, anamplifier 140, and an antenna 150. These components allow fortransmission of wireless signals from the BLE transmitter 100 to areceiving device.

The BLE standard defines 40 communication channels in the range of2.4000 GHz to 2.4835 GHz. Out of these 40 channels, 37 channels are usedfor communicating data and the last three channels (37, 38, and 39) areused as advertising channels to initialize connections and sendbroadcast metadata. The BLE standard defines a frequency hopping spreadspectrum technique in which the radio hops between channels on eachconnection event. A broadcaster device may advertise on any one of the 3advertisement channels. The modulation scheme defined for the BLEstandard is a Gaussian frequency shift keying (GFSK) modulation. To thisend, within each channel, a frequency deviation greater than 185 KHzabove the carrier frequency corresponds to a bit with a binary value of‘1’ and a frequency deviation less than −185 KHz corresponds to a bitwith a binary value of ‘0’.

The BLE packetizer 110 may receive a signal originated from a processorof a host device. Such a signal may include data or control parametersincluded in the signal transmitted by the BLE transmitter 100.

The oscillator 120 generates a radio frequency (RF) carrier signal thatmay carry the data signal generated by the BLE packetizer 110. Themodulated RF signal, carrying the data signal, is amplified by theamplifier 140 and then broadcast by the antenna 150. The conventionalpower source 130 is a battery.

The oscillator 120 may be a free-running oscillator, which may be usedto directly generate an RF carrier signal. Thus, a free-runningoscillator may replace a frequency synthesizer to generate an RF carriersignal. Utilization of a free-running oscillator may result in powersavings. In the BLE transmitter 100, the free-running oscillatorgenerates an RF carrier signal having a frequency within a specificportion of the wireless spectrum, e.g., the 2.4 GHz industrial,scientific, and medical (ISM) wireless spectrum band.

Typically, the oscillator 120, operating as a free running oscillator,is locked via a phase-locked loop (PLL) to a clock originating from acrystal resonator, such as the resonator 121. The resonator 121 may bealso included on a board hosting the processor of the IoT device. Theresonator 121 is typically a crystal resonator, a quartz resonator, or amicroelectromechanical systems (MEMS) based resonator which typicallyprovides a sufficiently accurate and stable time/frequency reference.However, for low-cost, ultra low-power, and small form-factor IoTdevices, it is desirable to omit such a resonator.

Further, the energy consumed by oscillators, e.g., for calibrationoperations, is used mainly from its phase noise requirements or thepower required for the onset of oscillation. The power consumption perphase noise requirement decreases proportionally to the quadrature of anoscillator's quality factor.

Oscillators discussed in the related art suffer from a number oflimitations, thus are not applicable in a design of IoT tags. Forexample, crystal oscillators are expensive, relatively large indimension, and difficult to assemble on low cost inlay substrates.Soldered on oscillators require additional chip (electronic circuitry)interfacing pins and require a dedicated substrate design. Integrated RCoscillators are cheaper to manufacture, but consume significantly morepower. On-chip inductor-based oscillators pose special metallization andchip area requirements. Inductor-based oscillator have their ownlimitations, including implementing a compact inductor for smallerdevices, since implementing the coils of such an inductor in a limitedspace is challenging. Accordingly, while employing an integratedoscillator within an IoT device would provide a conveniently low-poweroscillator for generating a carrier signal, its physical implementationpresents a number of design obstacles.

Furthermore, all of the above-mentioned are typically calibrated, atproduction, to a specific to nominal frequency used as a reference tothe radio. As such, their oscillation frequency is substantially fixed.

It would therefore be advantageous to provide a solution that wouldovercome the challenges noted above.

SUMMARY

A summary of several example embodiments of the disclosure follows. Thissummary is provided for the convenience of the reader to provide a basicunderstanding of such embodiments and does not wholly define the breadthof the disclosure. This summary is not an extensive overview of allcontemplated embodiments, and is intended to neither identify key orcritical elements of all embodiments nor to delineate the scope of anyor all aspects. Its sole purpose is to present some concepts of one ormore embodiments in a simplified form as a prelude to the more detaileddescription that is presented later. For convenience, the term “certainembodiments” may be used herein to refer to a single embodiment ormultiple embodiments of the disclosure.

Certain embodiments disclosed herein also include a temperature sensor,comprising: an inductor-capacitor (LC) oscillator configured; and alook-up table stored in a memory, wherein the look-up table contains aset of frequencies as a function of ambient temperature values, whereinwhen the LC oscillator is calibrated to a frequency from amongst the setof frequencies, the respective ambient temperature as stored in thelook-up table is retrieved.

Certain embodiments disclosed herein also include an oscillatorcalibration circuit comprising: an inductor-capacitor (LC) oscillator;and a first frequency locking circuit (FLC) coupled to an over the airsignal and to the LC oscillator, wherein the first FLC calibrates thefrequency of the LC oscillator using the over-the-air signal, whereinthe over-the-air signal is utilized by the first FLC to calibrate the LCoscillator based on a frequency of the over-the-air signal. oscillator,comprising: a single layer inductor disposed within a single layerinlay, wherein the single layer inductor is configured in a spiralpattern within the layer of the inlay, wherein an integrated circuit ismounted on the single layer inlay; and a capacitor included in theintegrated circuit, wherein the capacitor is connected to the singlelayer inductor.

Certain embodiments disclosed herein include an inductor-capacitor (LC)oscillator, including: a single layer inductor disposed within a singlelayer inlay, wherein the single layer inductor is configured in a spiralpattern within the layer of the inlay, wherein an integrated circuit ismounted on the single layer inlay; and a capacitor included in theintegrated circuit, wherein the capacitor is connected to the singlelayer inductor; and an oscillator calibration circuit wherein theoscillator calibration circuit calibrates a frequency of at least the LCoscillator using an over-the-air reference signal.

BRIEF DESCRIPTION OF THE DRAWINGS

The subject matter disclosed herein is particularly pointed out anddistinctly claimed in the claims at the conclusion of the specification.The foregoing and other objects, features, and advantages of thedisclosed embodiments will be apparent from the following detaileddescription taken in conjunction with the accompanying drawings.

FIG. 1 is a schematic diagram of a BLE transmitter.

FIG. 2 is a layout diagram of a substrate having an LC oscillator withan inductor implemented within an inlay according to an embodiment.

FIG. 3 is a block diagram of a system for determining an LC relativefrequency code based to a received over-the-air signal according to anembodiment.

FIG. 4 is a schematic diagram of a system for determining an updated LCrelative frequency code of an LC oscillator as function of temperatureaccording to embodiment.

FIG. 5 is a graph showing plots of frequencies as a function of ambienttemperatures for multiple oscillators representing extremes ofmanufacturing variations.

FIG. 6 is a block diagram of an oscillator calibration circuit designedaccording to an embodiment.

DETAILED DESCRIPTION

It is important to note that the embodiments disclosed herein are onlyexamples of the many advantageous uses of the innovative teachingsherein. In general, statements made in the specification of the presentapplication do not necessarily limit any of the various claimedembodiments. Moreover, some statements may apply to some inventivefeatures but not to others. In general, unless otherwise indicated,singular elements may be in plural and vice versa with no loss ofgenerality. In the drawings, like numerals refer to like parts throughseveral views.

A high quality factor of an oscillator yields smaller active circuitryto generate oscillation due to the reduced power required to compensatefor the inductor losses, and hence smaller oscillator frequencysensitivity to temperature variation as the temperature dependencedominance of the active device capacitance can be easily reduced byshunting by a metal capacitor. This can reduce or potentially remove therequirement for calibration due to temperature changes, as smallercircuitry of an oscillator will reduce the effects of changes in ambienttemperature.

FIG. 2 is an example layout, or floorplan, diagram of a substrate 205having an LC oscillator 210 with an inductor 230 implemented within aninlay 200. The LC oscillator 210 is disclosed within a single layerinlay 200. The single layer inlay 200 is an integrated circuit (or chip)215 connected to at least one antenna 220 and mounted on the substrate205. The substrate 205 is a single layer material, which may be a singlemetal layer or any appropriate integrated circuit mounting material,such as a printed circuit board (PCB), silicon, flexible printedcircuits (FPC), low temperature co-fired ceramic (LTCC), and the like.

The at least one antenna 220 connected to the chip 215 is configured totransmit and receive radio frequency (RF) signals, including at leastBLE signals. In an embodiment, the at least one antenna 220 can beutilized to harvest energy from radio signals at various frequencies,examples of which are provided below. The antennas 220 may be printedon, or etched into, the substrate 205.

The integrated circuit 215, in an embodiment, provides the functionalityof a wireless IoT device or tag. The integrated circuit 215 includes anumber of execution functions realized as analog circuits, digitalcircuits, or both. For example, the integrated circuit 215 can performfunctions, such as reading from and writing to memory, e.g., ofperipherals, and executing simple logic operations; tracking powerlevels; generating and preparing data packets for transmission; cyclicredundancy check (CRC) code generation; packet whitening;encrypting/decrypting and authentication of packets; converting datafrom parallel to serial; and staging the packet bits to the analogtransmitter path for transmission.

In a preferred embodiment, the integrated circuit 215 includes anoscillator calibration circuit (not shown in FIG. 2 ) that is coupled,in part, to the LC oscillator 210. The oscillator calibration circuitcalibrates the frequency of at least the LC oscillator 210 using anover-the-air reference signal. An example implementation of anoscillator calibration circuit is discussed with reference to FIG. 3 .

Typically, an LC oscillator 210 is an electrical resonator for storingenergy oscillating at the circuit's resonant frequency. The LCoscillator is realized as an analog circuit having an inductive elementand a capacitive element 240 connected together. According to thedisclosed embodiment, the inductive element of the LC oscillator 210 isan inductor 230 and the capacitive element is a capacitor 240. Theinductor 230 is implemented within the single layer inlay of thesubstrate 205. The inductor 230 is configured to use the integratedcircuit 215 connectivity as a via to generate multiple turns on thesingle-layered inlay to create an inductor coil. Thus, in an embodiment,the inductor 230 can be structured in a spiral pattern, which allowsmultiple windings without leaving the single layer of the inlay. Itshould be appreciated that implementing the inductor 230 with multipleturns on the single layered inlay allows for a reduction of arearequired by the inductor 230 to free more inlay area for use by theantenna(s) 220 as well as to have more confined magnetic fields thatensure minimal coupling to an adjacent antenna 220 structures and lesssensitivity to external materials in proximity. The multi-turn inductor230 further allows a boost in the inductor's quality factor.

In an embodiment, the capacitor 240 can be a dedicated capacitorincluded in the chip 215 and connected to the single layer inductor 230.In an embodiment, the capacitor is a configurable lowtemperature-sensitivity capacitor. In another embodiment, the capacitor240 is realized as the parasitic capacitance of various circuits (notshown) included in the chip 215. Parasitic capacitance is an unavoidablecapacitance that exists between the parts of an electronic component orcircuit simply because of their proximity to each other. Thiscapacitance can be captured and used as a capacitor 240 for the LCoscillator 210. In an embodiment, the LC oscillator 210 is configured tohave a high quality (Q) factor, which is a value describing howunderdamped an oscillator is. An oscillator with a high Q factor offershigh temperature stability, which allows the LC oscillator to becalibrated based on ambient temperature value, as further discussedbelow in FIGS. 4 and 5 .

An inlay-based inductor provides a Q factor which is significantlyhigher than that of an integrated (in-chip) inductor. Additionally,because of the minimal space requirements of an inlay-based inductor, itrequires minimal area use on a chip, and is more cost effective. In anembodiment, the frequency of the LC oscillator 210 is calibrated basedon a determined ambient temperature.

FIG. 3 is an example block diagram of a system 300 for determining anoscillator relative frequency code based to a received wireless signal310.

A wireless signal 310, such as a BLE or similar RF signal, is received,e.g., by an antenna 320. The received signal 310 is optionally amplifiedby an amplifier 330 to ensure a sufficiently strong signal, and then fedto a frequency-locked loop (FLL) 340 which is configured for a frequencymeasurement mode, i.e., with no feedback loop. An oscillator 350 output,such as from an LC oscillator, is compared to the received signal 310via the FLL 340, which is then output as an LC relative frequency code.The output code is determined based on both the received wireless signal310 and the LC oscillator 350 signal. The LC relative frequency coderepresents a derived frequency of the LC oscillator from its proportionto a known received signal frequency. For example, the signal receivedis at 2.402 GHz (BLE channel 37), and the LC free running is at 3.3 GHzand divided by 3000 to generate a 1.1 MHZ clock. After averaging ofseveral cycles of counting 2.402 GHz with this 1.1 MHZ clock, a resultof 2402/1.1=2183.64 represents the ratio between the clocks andindicates that the LC is oscillator is running at 3.3 GHz. In anembodiment, the LC oscillator is calibrated based on an ambienttemperature, values in the look-up table and a previously determined andcalibrated LC relative frequency. The ambient temperature may bedetermined based on the LC relative frequency code.

FIG. 4 is an example diagram demonstrating the determination of anupdated LC relative frequency code 440 of an LC oscillator based on themeasured ambient temperature.

In this embodiment, a temperature sensor 410 measures an ambienttemperature of an LC oscillator 405. The LC oscillator 405 is structuredand integrated within an IoT tag as discussed in FIG. 2 . A look-uptable 420 may then be accessed, which provides at least one set offrequencies and temperature values, where each frequency corresponds toa set temperature. The look-up table may be predetermined during themanufacture of the LC oscillator or the IoT tag. In an embodiment, thelook-up table 420 may be saved in a retention memory in the chip 215.FIG. 5 demonstrates a graph showing a set of frequencies as a functionof temperature values that may be included in the look-up table 420.

An LC relative frequency code 440 is determined based on both thelook-up table 420 frequency value associated with a currently detectedambient temperature, and on a previously determined and calibrated LCrelative frequency code 430. Such a frequency code 430 may be initiallydetermined during manufacture, and subsequently updated according to thedisclosed method. In an embodiment, the difference between a current LCrelative frequency code 440 and a previously determined LC relativefrequency code 430 is stored, e.g., in a storage of future reference,and may be used to predict future LC relative frequency codes.

This removes or significantly reduces the need for LC oscillatorcalibration using over-the-air reference signals. The high temperaturestability of a high Q factor oscillator allows for the accuracyrequirements from temperature sensors 410 to be significantly relaxed.This further allows for the addition of multiple active devices, e.g.,IoT devices, to enable the onset of oscillation. Some active devices,such as transistors, have much larger temperature dependency then metalinductors and capacitors, and are thus limited in their accuracy in realworld applications when implemented in non-temperature staticenvironment.

An inlay-based inductor provides a quality factor which is significantlyhigher than that of an integrated (in-chip) inductor. Additionally,because the inductor can be placed within the inlay rather than directlyon the chip, a smaller chip can used, and is thus more cost effective.In an embodiment, the LC oscillator is calibrated based on a determinedtemperature. Thus, based on a current temperature reading, e.g., from atemperature sensor, the frequency of the oscillator is calibrated.

In an embodiment, a reverse process may be implemented, where an LCoscillator produces a predictable temperature-to-frequency dependency sothat a temperature can be determined based on a measurement of the LCoscillator frequency. If the ambient temperature changes, thetemperature can be derived from an LC oscillator measurement based onthe look-up table 420. Thus, the LC oscillator may function as anaccurate temperature sensor. The capacitor of the LC oscillator mayfurther be adjusted store a lower amount of electrical energy, whichenhances the temperature sensitivity when used as a temperature sensor,as the overall power consumption is reduced. Adjusting the capacitoradditionally ensures avoidance from interfering signals, e.g., that cancause pulling, or avoidance of spectral emissions, e.g., for regulatorypurposes.

Various IoT devices may implement such an oscillator, and thus based onthe frequency of an LC oscillator integral to the IoT device, atemperature of the IoT device can be determined without an additionaltemperature sensor.

Such a configuration allows for an oscillator that has a low dependencyon the look-up table on the fabrication process, e.g., on thetransistors on a chip, for proper calibration. In an embodiment, anytransistors connected to the oscillator, e.g., through a chip of an IoTdevice, have a reduced effect on the oscillator frequency overtemperature behavior, when the oscillator possesses a sufficiently highquality (Q) factor. An LC oscillator that is stable in frequency versustemperature will provide superior output reference signals.

FIG. 5 is an example graph 500 showing plots 510 of frequencies 520 as afunction of ambient temperatures 530 for multiple oscillators,representing extreme manufacturing variations. As can be seen, the plotsare significantly parallel and may be aligned by using a singlecalibration adjustment. A predetermined plot graphing frequency as afunction of temperature can then be used for each of the oscillators.

It should be empathized that at production the LC oscillator is notbrought to an accurate frequency. Rather, at production, variouscalibration frequencies are measured and saved, e.g., within a look-uptable, where such frequencies can be later utilized for a recurringcalibration as discussed herein, for example, in FIG. 6 .

FIG. 6 shows an example oscillator calibration circuit 600 designedaccording to an embodiment. In this example embodiment, the oscillatorcalibration circuit 600 includes three frequency locking circuits (FLCs)610, 620, and 630 respectively calibrating oscillators 611, 621, and631. In an embodiment, one or more of these oscillators are LCoscillators, e.g., the LC oscillator discussed in FIG. 2 . In thisconfiguration, the calibration is performed sequentially. In a preferredembodiment, the oscillator 611 is an auxiliary oscillator realized as anLC oscillator and the oscillators 621 and 631 are realized as ringoscillators.

Specifically, the FLC 610 calibrates an LC oscillator 611 using anover-the-air reference signal 605. The signal 605 may be any of avariety of over-the-air reference signals. For example, such a referencesignal may be a BLE advertisement packet signal, an ultra-wideband (UWB)RFID reader signal in the 900 MHz bands, a 13.56 MHz RFID reader signal,a single tone reference at any of the industrial, scientific and medical(ISM) bands, a modulated reference at any of the ISM bands, an RF signalin the Wi-Fi spectrum (2.4 GHz or 5 GHz bands), an FM radio signal, aterrestrial TV signal, and cellular. In an embodiment, the LC oscillator611 is calibrated to output an LC signal 612 having a frequency of 1MHz. In an embodiment, the oscillator calibration circuit 600 includes asignal frequency detector for producing a reference signal based on areceived over-the-air signal, wherein the signal frequency detector isconfigured to detect a frequency of the over-the-air signal.

The output signal 612 serves as a reference signal to the FLC 620 whichcalibrates the oscillator 621. According to one embodiment, theoscillator 621 can be calibrated to output a single point carrierfrequency or two points carrier frequencies. Here, the output of theoscillator 621 may serve both as a carrier signal 623 for the BLEtransmitter and as a reference signal 622 for the FLC 630. The FLC 630calibrates a symbol oscillator 631 to output a symbol signal having afrequency of 1 MHz. The symbol signal is utilized to modulate the datato be transmitted.

Each of the FLCs 610, 620, and 630 can modulate the signal to varyingdegrees. In this embodiment, the calibration is performed immediatelyprior to a transmission session, while the transmission of all FLCs andoscillators are free running. To this end, each of the FLCs 610, 620 and630 are enabled immediately prior to a transmission session.

It should be appreciated that the oscillator calibration circuit 600demonstrates high frequency accuracy and low power consumption. This isbecause the oscillator 621 and symbol oscillator 631 are calibratedusing an available high frequency accurate signal over the airreference, such as 2.4 GHz, and via the high quality (auxiliary)reference oscillator. As such, the calibration time is short, whichresults in less energy consumption.

The utilization of the LC oscillator allows for overcoming frequencypulling. This phenomenon occurs when the reference signal utilized tocalibrate the local oscillator is received through the same antennautilized to transit the carrier signal (generated by the localoscillator). Frequency pulling typically changes the oscillatingfrequency. By adding another calibration stage, through the LCoscillator, the reception of the reference signal is decoupled from thetransmission of the carrier signal.

It should be noted that the oscillator calibration circuit 600 can beconfigured in another arrangement. For example, the FLC 610 could beutilized for calibration of both FLCs 620 and 630.

It should be further noted that the oscillator calibration circuits 600,designed according to the disclosed embodiments, do not include anyexplicit discrete or assembled resonator component, such as a crystalresonator, a quartz resonator, or a MEMS-based resonator.

In an embodiment, the LC oscillator is calibrated according to methodsdiscussed in U.S. patent application Ser. No. 15/994,388, now pendingand assigned to the common assignee, which is hereby incorporated byreference.

As used herein, the phrase “at least one of” followed by a listing ofitems means that any of the listed items can be utilized individually,or any combination of two or more of the listed items can be utilized.For example, if a system is described as including “at least one of A,B, and C,” the system can include A alone; B alone; C alone; A and B incombination; B and C in combination; A and C in combination; or A, B,and C in combination.

All examples and conditional language recited herein are intended forpedagogical purposes to aid the reader in understanding the principlesof the disclosed embodiment and the concepts contributed by the inventorto furthering the art, and are to be construed as being withoutlimitation to such specifically recited examples and conditions.Moreover, all statements herein reciting principles, aspects, andembodiments of the disclosed embodiments, as well as specific examplesthereof, are intended to encompass both structural and functionalequivalents thereof. Additionally, it is intended that such equivalentsinclude both currently known equivalents as well as equivalentsdeveloped in the future, i.e., any elements developed that perform thesame function, regardless of structure.

What is claimed is:
 1. A temperature sensor, comprising: aninductor-capacitor (LC) oscillator; and a look-up table stored in amemory, wherein the look-up table contains a set of frequencies as afunction of ambient temperature values, wherein when the LC oscillatoris calibrated to a frequency from amongst the set of frequencies, therespective ambient temperature as stored in the look-up table isretrieved.
 2. The temperature sensor of claim 1, wherein the LCoscillator comprises: a single layer inductor disposed within a singlelayer inlay, wherein the single layer inductor is configured in a spiralpattern within the layer of the inlay, wherein an integrated circuit ismounted on the single layer inlay; and a capacitor included in theintegrated circuit, wherein the capacitor is connected to the singlelayer inductor.
 3. The temperature sensor of claim 2, wherein, the LCoscillator has a high Q factor based on usage of the single layer inlayinductor.
 4. The temperature sensor of claim 1, wherein an LC relativefrequency code is determined based on both the look-up table frequencyassociated with a currently retrieved detected ambient temperature andon a previously determined and calibrated LC relative frequency code. 5.An oscillator calibration circuit, comprising: an inductor-capacitor(LC) oscillator; and a first frequency locking circuit (FLC) coupled toan over-the-air signal and to the LC oscillator, wherein the first FLCcalibrates the frequency of the LC oscillator using the over-the-airsignal, wherein the over-the-air signal is utilized by the first FLC tocalibrate the LC oscillator based on a frequency of the over-the-airsignal.
 6. The oscillator calibration circuit of claim 5, furthercomprising a second FLC circuit coupled the LC oscillator and to asecond oscillator, wherein an output signal of the LC oscillator servesas a reference signal for the second oscillator; and wherein the firstFLC and the second FLC are configured to impact modulation of thereference signal by the second oscillator.
 7. The oscillator calibrationcircuit of claim 5, wherein the oscillator calibration circuit does notinclude any assembled resonator component.
 8. The oscillator calibrationcircuit of claim 5, wherein the LC oscillator further comprises: asingle layer inductor disposed within a single layer inlay, wherein thesingle layer inductor is configured in a spiral pattern within the layerof the inlay, wherein an integrated circuit is mounted on the singlelayer inlay; and a capacitor included in the integrated circuit, whereinthe capacitor is connected to the single layer inductor.
 9. Aninductor-capacitor (LC) oscillator, comprising: a single layer inductordisposed within a single layer inlay, wherein the single layer inductoris configured in a spiral pattern within the layer of the inlay, whereinan integrated circuit is mounted on the single layer inlay; and acapacitor included in the integrated circuit, wherein the capacitor isconnected to the single layer inductor; and an oscillator calibrationcircuit wherein the oscillator calibration circuit calibrates afrequency of at least the LC oscillator using an over-the-air referencesignal.
 10. The LC oscillator of claim 9, wherein the single layerinductor is configured to use the integrated circuit as a via togenerate multiple turns to create an inductor coil of the single layerinductor.
 11. The LC oscillator of claim 9, wherein, during productionof the LC oscillator, at least one frequency of the LC oscillator ismeasured based on an ambient temperature value.
 12. The LC oscillator ofclaim 11, wherein a set of frequencies of the LC oscillator andrespective temperature values are saved in a look-up table.
 13. The LCoscillator of claim 12, wherein during operation a frequency of the LCis derived based a frequency measured during production and informationsaved in the look-up table.
 14. The LC oscillator of claim 12, whereinthe LC oscillator is further calibrated based on an ambient temperature,values in the look-up table and a previously determined and calibratedLC relative frequency.
 15. The LC oscillator of claim 9, wherein the LCoscillator is further connected to at least one antenna through theintegrated circuit.
 16. The LC oscillator of claim 15, wherein afrequency of a signal of the oscillator is measured using signalsreceived through at least one antenna.
 17. The LC oscillator of claim16, wherein the measured frequency of the LC oscillator is a relativefrequency code.
 18. The LC oscillator of claim 17, wherein an ambienttemperature at the LC oscillator is determined based on the LC relativefrequency code.
 19. The LC oscillator of claim 9, wherein the capacitoris a dedicated capacitor included in the integrated circuit, wherein thededicated capacitor is a configurable low temperature-sensitivitycapacitor.
 20. The LC oscillator of claim 9, wherein the capacitorincludes parasitic capacitance from circuits included in the integratedcircuit, wherein a dedicated capacitor is connected in parallel to theparasitic capacitance.
 21. The LC oscillator of claim 9, wherein thecapacitor is adjusted to store a lower amount of electrical energy andincrease a temperature sensitivity of the LC oscillator.